EDIT: I solved the problem. It's the last thing I could think about...Windows Firewall !!!
I'm hosting a Windows 2008 Server virtual machine on Ubuntu server 12.04 LTS using virtual box 4.1.18. The windows guest adapter is bridged on ubuntu's eth0 NIC and is pingable from the host (ubuntu server) and other machines on the same network. Also the guest (windows 2008 server) can ping the host and other machines on the network.
But neither the host nor other machines can access a web application hosted on the guest (http, port 80). Using the guest's IE browser, I can access the application so it's functioning already.
I tried setting the promiscuous mode for the guest's NIC:
VBoxManage modifyvm "Win2008Server_x64" --nicpromisc1 allow-all, but that didn't do the trick.
iptables rules indicate that all traffic is allowed "as Ubuntu should be by default":
root@mysql:~# iptables -L Chain INPUT (policy ACCEPT) target prot opt source destination Chain FORWARD (policy ACCEPT) target prot opt source destination Chain OUTPUT (policy ACCEPT) target prot opt source destination root@mysql:~# iptables -S -P INPUT ACCEPT -P FORWARD ACCEPT -P OUTPUT ACCEPT
About port forwarding, I don't need to do that because I'm bridging the guest's NIC over the host's NIC, correct ?
On a virtual machine, I had tomcat7 running using port 8080. So I changed the webserver's port from 80 to 8080 but that didn't work either so I guess It has nothing to do with ubuntu. It's something about the virtual machine configuration but I can't figure it out !